Hi. I have a 17" intel imac 512ram running 7.2 at home and use a variety of different macs at work including dual ppc G5 towers running 7.1 (I teach at a music college). For my money my intel imac, despite having considerably less Ram is smoother and more stable than the machines at work. I get the occasional crash usually when changing exs24 programs without stopping the sequencer. Apart from that no problems at all. It's quiet, stable and powerful. I don't know what problems others are experiencing as I haven't had cause to visit forums because i haven't had any problems. J.